Ecology

What is Ecology? Ecology is the study of interactions among organisms and their environments, or surroundings – also includes the study of human interactions and the impact of human activities on the environment

The Biosphere The combined portion of the planet where life exists -land, water, atmosphere ect… -extends 8 kilometers above Earth’s surface and 11 kilometers

Levels of Organization within the Biosphere Species- group of organisms so similar they can interbreed and produce fertile offspring Population- group of organisms of the same species living in the same area Community- collection of all species populations living in the same area Ecosystem- living community + nonliving physical environment – Abiotic- nonliving factors Climate, sunlight, soil composition, nutrients ect… – Biotic- living organisms community Biome- group of similar ecosystems with similar climate and similar communities – Usually cover a large geographic area

Energy with Ecosystems Producers (autotrophs)- organisms capable of making their own energy supply – Plants on land and algae in water (photosynthesis) Consumers (heterotrophs)- organisms that rely on other organisms for food supply (must consume other organisms to obtain energy supplies – Herbivores, carnivores, omnivores, detritivores ect… – Primary, secondary, tertiary ect… Decomposers- obtain energy by breaking down organic matter – Bacteria & Fungi – Very important- return nutrients to abiotic environment (soil)

Relative Importance Which class of organisms do you feel are most important and why? – Producers- most vital (important) make energy for themselves all other organisms in their ecosystems. WITHOUT PRODUCERS there is NO OTHER LIFE! – Decomposers- very important because they break down organic matter Return nutrients to soil/abiotic environment – Consumers- complete the “balance of life” yet are least important

The Food Chain Series of steps that show feeding relationships and flow of energy through an ecosystem – Each STEP IN FOOD CHAIN = TROPHIC LEVEL – Starts with producer Convert energy from sunlight

Food Webs Show all the feeding relationships or interconnected food chains within an ecosystem

Flow of Energy Through an Ecosystem er_detailpage&v=De_53QflEXQ

Flow of Energy Through an Ecosystem Energy Flows Through an ecosystem in ONE DIRECTION. – It is not recycled! Organisms use approximately 90% of the energy they take in for metabolic activity (life processes) – Most of this energy is lost to the environment as heat. Only about 10% of the energy that an organism takes in is stored in its structures and available for organisms at the next trophic level (step of the food chain) This relationship can be shown in an energy pyramid

The ENERGY Pyramid

Matter vs Energy Unlike Energy, MATTER is RECYCLED in nature – Matter Cycles between abiotic (nonliving environment) and community (living things) Common Substances Cycle in Nature. – Water – Carbon – Nitrogen – Phosphorus

The Water Cycle Evaporation, Transpiration, Condensation, Precipitation, Water Runoff

The Carbon Cycle In Atmosphere (CO 2 ), Photosynthesis, Food Chain (sugars), Respiration, 3D’s (Death, Dung, and Decay) Burning of Fossil Fuels

The Nitrogen Cycle In Atmosphere (N 2 ), Nitrogen Fixation, Plant Uptake, Food Chain, 3 D’s (Death, Dung, and Decay), Denitrification

The Phosphorus Cycle In Soil, Rocks, and Bodies of Water Plant Uptake, Food Chain Death, Dung and Decay

Weather vs Climate Weather- day to day a particular time and place Climate- average yr after yr conditions at a particular place – Average temperatures (fall,winter, spring, summer) – Precipitation- amount of rainfall, snow, hail ect..

Effect of Climate on Ecosystems Climate shapes Ecosystems! – Climate is the #1 Abiotic Factor that determines what type of community that will be found in a particular area. – Temperatures and rainfall determine what type of plants (plant life) can be found in an area This also determines the type of animals and # of animals that can be found in an area

Solar Radiation Heats Earth Earth Heats Atmosphere Some Heat Trapped in Atmosphere by Greenhouse Gases CO 2, CH 4, and N 2 O Without greenhouse effect Earth would be VERY COLD!

Effect of Latitude on Climate Near equator the angle of solar radiation is more direct More solar radiation will penetrate the atmosphere near equator – Warmer an d wetter as a result 3 distinct zones created (tropical,temperate, and polar)

Biomes of the World

The Niche An organism’s “role” within the ecosystem – Feeding Relationships Where does it belong in food chain – Physical requirements (temperature, shelter, ect…) – Other relationships with other species

Community Interactions Competition- organisms of the same or different species trying to use the same resource at the same time – Water, nutrients, light, food, space ect… Predation-one organism captures and feeds upon another organism – Ex: Deer and wolf Predator-Wolf Prey-Deer

Community Interactions Cont… Symbiosis-when two organisms live close to one another and have some sort of Relationship – Mutualism- a relationship in which both species benefit Ex: Oxpecker and cattle – Commensalism- a relationship in which one species benefits and the other is neither helped not harmed Ex: Tree and bird – Parasitism- a relationship in which one species benefits and the species is harmed Parasite vs Host Ex: Tapeworm (parasite) and Animals (Host)

Ecological Succession Ecological Succession- changes in a community after human or natural disturbances – Usually changes are predictable – Simple to complex – Can be Primary or Secondary

Primary Succession Primary succession- no soil present – Follows volcanic lava flows or eruptions – Pioneer species- 1 st species to populate the area Lichens, bacteria Other species follow as rock is weathered to create soil that is suitable – Lichens  grasses  small shrubs  trees ect… – This process is SLOW – Eventually Reaches Climax Community Climax Community- steady community with lots of diversity and many community interactions

Secondary Succession Secondary Succession- Soil is already present – Follows Forest Fires, Floods, Changes in Abiotic Environment, Human Disturbances ect.. – Occurs much, much faster than primary succession Soil is already present

IF YOU STUDY ALL 1-30 SLIDES HARD…YOU ARE AN EXCELLENT STUDENT AND WILL BE PREPARED

Population Growth 4 Factors that influence the growth of a population – Immigration- individuals moving Into a population – Emigration- individuals leaving or Exiting the population – Birth Rate- Individuals being born per year – Death Rate- individuals dying per year

Types of Population Growth Exponential Growth – Continuous growth Must have unlimited resources and no limiting factors restricting a populations size/growth -not usually realistic in nature

Types of Population Growth Logistic Growth – begins w/ rapid grow exponential phase – Carrying Capacity- max # of individuals that ecosystem support – growth rate slows as population size nears carrying capacity. WHY? Limiting Factors- limit pop. growth – predation, competition, parasitism & disease – Natural disasters, unusual weather and/or climate change, and human activity

Logistic Growth (cont.) Slight fluctuation near carrying capacity is normal Population could “crash” and reenter exponential phase

Biodiversity All the different species living on Earth – Human activity has significantly lowered the amount of biodiversity on Earth. – Are we currently causing a mass extinction? – Extinction is a natural process but… It is estimated that human activity has increased the rate of extinction by 1,000 to 10,000 times the natural rate 30-50% of all species will be extinct by mid century (2050)

Who Cares? Human survival is tied to biodiversity – Humans are dependent upon living things for: Natural resources Food and goods Pharmaceuticals (medicines)

Human Actions Habitat Destruction/Alteration- This is the leading cause of extinction. – Urban development – Industrial development – Dams/Alteration of Aquatic Environments – Agricultural Development Deforestation Habitat Fragmentation- splitting of ecosystems into pieces (islands) – many organisms such as GRIZZLIES need a large area to survive. Fragmentation can equal extinction

Overfishing/Overhunting/Poaching

INVASIVE (nonnative) SPECIES Introduction of Invasive (nonnative) species has a negative impact on ecosystems – Invasive species can outcompete native species and disrupt balance or relationships within a natural ecosystem

Pollution – Acid Rain Chemicals within smog combine with water from rain to form nitric and sulfuric acid – Changes acidity of marine systems and terrestial systems – Toxic Waste – Biological Magnification- build up of toxins as they pass through food chain Some toxins do not degrade These toxins reach lethal level as they reach upper levels of a food chain Example- DDT

OZONE DEPLETION CFC’s and other Air Pollutants destroy the ozone layer – Ozone (O 3 ) is in the upper layer of the atmosphere and deflect much solar and UV radiation CANCER KILLS ALSO Contributes to global warming

GLOBAL WARMING Burning of Fossil Fuel INCREASES CO 2 levels in the atmosphere – CO 2 is a greenhouse gas and traps heat – Excess CO 2 is causing global climate change is taking place

Conservation Efforts Today, focus is on saving entire ecosystems in addition to single species – Ecological Reserves – National Parks Ect… – Doing so preserves relationships in nature and provides an increased chance of saving many species.

What have you done lately? Interested in more? – AP Environmental Science